Door lock



July 26, 1960 J. H. ROETHEL 2,946,613

DOOR LOCK Filed May 31, 1956 2 Sheets-Sheet 1 4 INVENTOR, .3 4 52;, xv. zfiezkz, E-

July 1960 J. H. ROETHEL 2,946,613

DOOR LOCK Filed y 51, 1 2 Sheets-Sheet 2 A position.

noon LOCK John H. Roethel, Coral Gables, Fla. (20200 Mansfield, Detroit 35, Mich.)

Filed May 31, 1956, Ser. No. 588,481

7 Claims. (Cl. 292-229 This invention relates to a latch mechanism for swinging doors, particularly the doors of automobiles or other vehicle bodies, an object of the invention being to provide an improved door latch mechanism which is characterized by. its simplicity and compactness of construction and which is relatively small in size, economical to manufacture, comparatively quiet in operation and efficient in use.

More particularly, the present invention is embodied in an improved door latch mechanism having a pivoted or swingable latch device, a pivoted dog or detent cooperable therewith, and shiftable detent release means mounted on a supporting plate or the like at the free edge wall of the door, the detent release means being operable from either the outside or the inside of the door.

It is an object of the present invention to provide an improved mechanism for rendering the detent release means inoperable from the outside of the vehicle door to release or disengage the detent from the latch device, said mechanism comprising a movable blocking member preferably mounted on a flange extending from the inner edge of the supporting plate, said blocking member being normally spring urged into non-blocking position, and inner manually operable means operative to move and retain said blocking member in blocking position, said inner manually operable means also being operative to actuate the detent release means to cause the latter to disengage the detent from the latch device.

In a first embodiment of the present invention, the blocking member may be placed in blocking relation to the detent release means regardless of whether or not the latch device is in door latched or door unlatched Thus, in this embodiment the latch mechanism may be placed in door locked condition if the door is opened or closed. If the blocking member is placed in door locked condition when the door is open, the door may be closed without disrupting the relationship of the blocking member to the detent release means.

In a second embodiment of the invention herein illustrated, the blocking member may only be placed in blocking relationship to the detent release means when the latch mechanism is in door latched condition. In this embodiment, a portion of the detent release means is adapted to block movement of the blocking member into blocking relationship as long as the latch mechanism is in door unlatched condition. After movement of the latch mechanism from door unlatched to door latched condition, such as occurs when the door is moved from its open to a closed position, the blocking member may then be moved into blocking relationship relative to the detent release means.

Further objects and features of the particular embodiments of the invention herein illustrated will appear in the following description, reference being had to the accompanying drawings forming a part of the specification wherein like reference numerals designate corresponding parts in the several views.

Fig. l is an elevation showing the latch mechanism Patented July 26, 1960 parts mounted on the inner side of the latch mechanism support plate. 7

Fig. 2 is a section taken substantially through lines 2-2 of Fig. 1 looking in the direction of the arrows.

Fig. 3 is a view taken substantially in the direction of the arrows 3-3 of Fig. 4 showing in solid outline the relationship of the latch mechanism latch bolt to a striker or keeper device when the latch bolt is in door latched position.

Fig. 4 is a section taken substantially through lines 4-4 of Fig. 3 looking in the direction of the arrows.

Fig. 5 is a view substantially similar to Fig. 2 illustrating parts of the latch mechanism in door locked position.

Fig. 6 is a view in part similar to Fig. 1 illustrating a second embodiment of the present invention.

Fig. 7 is a view taken substantially through line 77 of Fig. 6 looking in the direction of the arrows.

Before explaining in detail the present invention it is to be understood that the invention is not limited to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments, and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed therein is for the purpose of description and not of limitation.

In the drawings there is illustrated, by way of example, particular embodiments of the present invention as applied to the doors and frame structures of an automobile body. The latch device embodied in Figs. 1 to 5 inclusive comprises a case plate 14 provided with screw bosses 11 by means of which the case plate id is secured to the inner side of the jamb portion or free edge wall 12 of a vehicle door. The case plate 10 terminates. at its inner edge in a flange 13 which is adapted to be positioned along the inner panel of the door. The latch mechanism is provided with a latch bolt 14 positioned at the outer side of the case plate in. This latch bolt 14 is a lever-like or finger-like element which will be described in greater detail. The latch bolt 14 is mounted on a shaft 15 extending through an aperture in the case plate, suitable bearing means being provided to journal the shaft in the case plate.

Rigidly mounted on the other or inner end portion of the shaft 15 is a rotatable detent engaging member or ratchet member 16. The ratchet member 16 is formed on its periphery with spaced abutments or teeth 17 and 18. Pivotally mounted on a shoulder rivet 19 secured to the case plate 10 is a swinging detent, pawl or dog 20, which has a downwardly extending portion 21 engageable with the abutments or teeth 17 and :18. When the bolt 14 is in unlatched position an abutment 22 on the ratchet member 16 is adapted to be in'engagement with a stop lug or pin 23 mounted on the case plate. 10. When the ratchet member 16 has been rotated in a clockwise direction, as viewed in Fig. 1, to place the detent portion 21 in engagement with the abutment '17, the bolt 14 is said to be in safety locking position. And, when the detent portion 21 is in engagement withthe abutment 18, as shown in Fig. 1, the latch bolt 14 is in final locking position.

Associated with the detent 20 is a detent actuating or release lever 24 which is pivoted upon the shoulder rivet 19, so as to be swingable about a common pivot axis with the detent 20. The release lever 24 has a downwardly extending arm 25 terminating in a lateral flange 26 positioned for engagement by a plunger or the like which may be shifted inwardly to swing the lever 24 about its pivot 19 by any suitable manually operable means on the outside of the door such, for example, as a handle or by any other preferred means such as a push button associated with an outside door handle. The release lever 24 has an inwardly extending arm or portion 27 having appended thereto an extension 28 reaching to the support flange 13. The'flange l13'niay'beslotted, -as-at 29, to provide clearance for the extension end "28of the 27. The detent 20 is yieldinglynrged -toward the ratchet member '16 and the detent release lever 24 is-urged out- 'wardly toward its retracted position,as showninFig. 1, :by m'eans of a common spring 30. The-spring "30*hasa "horizontally extending arm 31 the'end of which'cng'ages a lug 32 on the detent 20. The detent lug 32 pro'jects through an aperture 33 in the'arm 27' of the releaselver. Tlielu'g 32 abuts the lower edge of the aperture '33. The "in'nenend of the spirallywound coil po'rtion 34 'ofthe spring 30 is secured to a notched'portion o'rkerf 35 of the pivot stud 19. The effort exerted by the spriiig 30 "in urging the detent 20 into engagement with the ratchet member 16, as shown in Fig. 1, will be transmitted through the lug 32 to the abutting 'ed ge ofthe detent release lever 24, thereby urging the'latter't'owafd its 'retracted position. The finalretracted position of'the release lever 24- is determined by the lower edge of the "extension 28 thereof abutting the lower edge of the slot 29 in the flange. It should alsobenoted that the down- 'wardly extending arm 25 of the release lever 24 is'off-set so that it will pass over the stop 23, the stop pin 23 having 'only the functionof limiting the'extent of movementof the ratchet 16 in a clockwise direction as viewed in Fig. l.

Pivoted to the case plateflange13,-by-"means er a pivot stud or shoulder rivet 36, is' a bellcrank lever-37 having an upwardly extending arm 38 and a generally j'horizontally extending arm 39 extending in the direction of the case plate 10 and of 'suflicient length-to under-lie the extension 28 of the release lever 24. The present latch mechanism is preferably operated "from the inside of the door through the medium'of a remote control mechanism including a longitudinally 'shiftable draft link 40 which is pivotally connected by rivet means 41 to the upper end of the bellcrank arm 38. 'The remote control mechanism is preferably manually actuated from the inside of the door remote from the 'case plate 10 by means of a door-handle (not shown) which may be swung in a desired direction. It'will be understood that by swinging the lever 37- in a counterclockwise direction, as viewed in'Fig;-2, the arm 39 will feng age the extension 28 of the release'leventhereby pausing the release lever to pivot about its pivotal axis -19 in" a clockwise direction as viewed in Fig." l. Through the abutting relationship of the lug 32 with the edge 'bf lthEfiPfil'tlll'e 33 in the release lever arm 27, swinging movement of the release lever in aclockwise" direction will cause'the'detent 20 to be swung upwardly out of engagement with'the ratchet teeth. Thereby, the ratchet 'iS free to move in door unlatching direction. 'A similar detent disengaging movement occurs whendherele a'se lever 25 is swung toward the case plate flange-d3 by operation of the outside door handle, push button or the like, the motion of the release lever being-transmittedto the detent through the abutting relationship of the edge of the detent arm 27, aperture 33 and the detent lug 32. A spirally wound spring 42 having its inner 'end seated in a notch or kerf 43 inthe inner endof the shaft 15 and its outer end hooked on to a lug 44 turned 'upwardly from the case plate flange is provided to'ensure retraction of the latch bolt to its unlatched position upon release of the detent arm 21 from the ratchet member 16. jIn the latch mechanism'illustrated in the embodiment 'of Figs. 1 to 5 inclusive, means is provided for restraining or blocking the detent release lever 24 against movement injdetent disengaging direction by the means manually operable from the outside of the door. The" blocking ,rneanscomprises a lever means, ger'rerally designated 45. The blocking lever means45 is pivotallymoun'ted"onthe it dropsinto final locked position.

case plate flange 13 by means of a shoulder rivet or pivot stud 46. As best viewed in Fig. 2, the blocking lever comprises a member having an upwardly extending arm 47 terminating in a hook portion 48 adapted to overlie the extension 28 of the release lever arm 27. The blocking lever 45 has a second angularly inclined upwardly extending arm 49 adapted to underlie the bell crank lever arm 39. The arm 49 terminates in a lug 50. As shown in Fig. 2, the blocking lever 45 'iscontinually urged by a spring 51 so'that its arm '47lies in abutting relation to the case plate flange 13. Thespring "51'has its inner end seated in a notch or kerf 52 in the shoulder rivet 46. The free e'rid'53 ofthe'sprin'g is provided with a hook adapted to hook over the lug 50 of the arm 49 of the blocking lever.

To place the latch mechanism in door locked position the blocking lever 45 must be moved from the position "shown in Fig. 2 to theposition shown in'Fig. 5. This is accomplished through the remote control mechanism, as 20 link 40 to the right, asviewed in Fig. 5, resultsin the bellcrank lever beingswung in a clockwise dire'ction. The'arm 39 of -thebell crank lever 37 'willabut the lug represented bythe draft link 40. Movement of the'draft 50 of the blocking lever 45 urging the arm '49 of the blocking lever in a downward direction causing the blocking lever to be swung in a counter-clockwise direction as viewed in Figs. 2 and '5. The -hook portion-48 of the blocking leverarm 47 will hook over theextension 28 of swuhgin a direction so as to shift the draft link 40 to i the right, as viewed-in Figs. 2 and 5,' the-draft link will -beheldinits shifted position by suitable' means' within the remote control mechanism. This isconventional structure well'known in the prior art and therefore is notbeinge'xplained in any greater detail. -AS10ng as 0 the draftlink 40 and the bell crank lever 37' are held in -tive to restore the blocking lever 45 to its non-blocking positionfthe position shown in Fig. 2. As soon as the remote control-"mechanism is restored'to a neutral posinon, so that the' draft link 40 and the bell crank lever the position shown in Fig 5, the spring 51 will be in'eifec- 37 are able to reassume the position shown in'Fig. 2, the

' s'pring' 51 will immediately kick the blocking lever 45 f over' town-blocking position, the position shown'in Itwil1 be noted in this embodiment that the detent 20'is movable independently of the release lever 24.

20 will merely ride over the teeth on the'ratchet 16 until The up and down movement of'the detent portion 21 is not reflected in any movement of the detent release lever 24, since the lug 32 on the detent arm 21 will merely move up and down jwithih the aperture 33 in the detent release lever arm 27. Thus,in this embodiment the remote control handle may be moved to door locked condition even if the dooris in opened or door unlatched condition.

Although, by so doing, the release lever 24 may be blocked against swinging movement in a clockwise direction as viewed in Fig. 1,

the detent 20 remains freely movable as the ratchet 16 turns upon the latch bolt engaging the striker or keeper upon the door being moved to a closed position.

The second embodiment'of the invention, that is illustrated in Figs. 6 and 7, shows a construction and ar "rangement wherein the release lever 24 may be blocked 'agaihst'disengagement of the detent 20 from the ratchet "only when the vehicle door is in closed position, that is,

the latch bolt is in door latched position. bodiment the'detentar-m 21 is coupled to the release lever In this emarm 27 by a rivet 54. Further, theratchet herein desigshown on the previously described ratchet 16. In all other respects the construction of the present embodiment is similar to that of the previously described embodiment.

The operation of the embodiment shown in Figs. 6 and 7 is as follows: To release the detent portion 21 from the ratchet teeth 17 or 18, the detent release lever means 24 must be swung in a clockwise direction as viewed in Fig. 6. This may be done by exerting from the outside of the vehicle door a force on the flange 26 of the arm 25 o f the detent release lever 24 to swing the arm :25 toward the flange 13. Or, from the inside of the door the release lever may be swung in a clockwise direction by actuation of the remote control mechanism in such a manner as to cause the bell crank lever arm 39 to engage the underside of extension 28 of the release lever arm 27 thereby causing the arm 27 to be raised upwardly. Upon movement of the detent portion 21 out of the path of the ratchet teeth 17 or 18, spring 42 will cause the bolt 14 and ratchet 16 to be thrown to door unlatched position. When in such position, as shown in Fig. 6, the detent portion 21 will ride upon the high spot 56 of the ratchet. Since the detent 2a and the release lever arm 24 are riveted together by the rivet 54, the release lever 24 will be maintained in angular relationship to its normal retracted position. The extension 28 of the release lever arm 27 will lie in the path of the hook portion 48 of the blocking lever 45. Even if the remote control mechanism is actuated so as to attempt to swing the blocking mem-' ber 45 in a counter-clockwise direction as viewed in Fig. 7, the abutting relationship of the extension 28 to the hook portion 48 will prevent the blocking lever 45 from being moved into blocking position.

Only when the vehicle door has been moved from an open to a closed positon so that the latch bolt 14 is moved from door unlatched to door latched position will the detent portion 21 permit the detent 2t) and thereby the release lever 24 to drop to their normal retracted position. It is in this position that the hook freely passes over the top of the release lever arm extension 28. If desired, the depth of the safety tooth 17 on the ratchet 16 may be such that the downward movement of the detent and ;release lever resulting from movement of the latch bolt to safety latch position would be insuflieient to permit the hook portion to pass over the top of the extension arm :28. Only the final locking tooth 18 would have sufficient .depth to permit the detent 2t and release lever 24 to sv/-ing fully to retracted position.

As was briefly stated in the foregoing the latch bolt device 14 is a lever-like or finger-like element. The latch bolt 14 has a substantially figure eight contour. The latch bolt is pivotally mounted on the case plate 11) by means of the shaft 15, the pivot axis being substantially at the center of the upper portion 57 of the bolt. When the latch bolt 14 is in door latched position it extends in a substantially vertical direction and is swingable in a plane parallel to the front face of the case plate 10. The latch bolt *14 has two other possible positions in which it may be maintained as illustrated in dot and dash outline in Fig. 3. When the latch bolt lies along the line 58 it is in unlatched position. When the latch bolt lies along the line 59 it is in the safety latched position. In other words, when the detent portion 21 is engaged with tooth 18 of the ratchet 16, the latch bolt will have the position shown in solid outline in Fig. 3. When the detent arm 21 is in engagement with the tooth 17 of the ratchet 16, the latch bolt will have the position along the line 59 shown in Fig. 3, which position corresponds to the safety latching position. And, when the detent arm 21 lies ,against the periphery of the ratchet 16, as it-will when the abutment 22 is in abutting relation to the stop pin 23, the latch bolt will have the position shown in Fig. 3 in "which it lies along the line 58. The latch bolt is moved from door unlatched condition to door latched condition by engagement with a striker device, generally designated 60.

The striker or keeper device 60, as best seen in Fig. 3, has in general the form of the letter 0 open to the outside. It is preferably made of a unitary piece of material and comprises an upper or head portion 61 having a substantially fiat lower surface 62, a descendent or erect rib 63 and a foot portion 64 of essentially hook form. The rib 63 is provided with a cam section 65 located intermediate the upper :and lower portions of the striker.

When the latch bolt is in door unlatched condition and the door is moved from an opened to a closed position the lower portion 66 of the latch bolt is adapted to engage the cam portion 65 of the rib 63. Thus, as the door is continued in its direction of closing movement thelower portion 66 of the latch will be swung in a clockwise direction, as viewed in Fig. 3, so that the lower portion 66 of the latch bolt nestles within the pocket 67 of the hook portion 64 of the keeper or striker 60. Swinging movement of the latch bolt 14 about its pivot axis 15 is transmitted through the shaft 15 to the ratchet 16 causing the latter to be swung in a counter-clockwise direction as viewed in Fig. 1. Should the closing movement of the door be halted upon the detent 20 passing over the tooth 17, the door would be said to be in safety latched position. The latch bolt would have only moved from the line 58 to the line 59 and although it would be retained within the striker, it would only be relatively loosely held therein. When the door is completely closed, the detent 20 is in abutting relation to the tooth 18 of the ratchet 16, and the latch bolt Will be in relationship to the striker in the position as shown in Fig. 3. It will be noted that the distance between the lower surface of the upper head portion and the bottom of the recess o-r pocket 67 in the hook portion is substantially equal to the longitudinal length of the latch bolt 14. The fit of the latch bolt within the confines of the striker must necessarily be a rather accurate one thereby preventing the door from being movable in a substantially up and down direction when the door is in door'latched condition.

The striker 60 is provided with a steel plate 68 which substantially closes off the one side of the striker, as shown in Fig. 4. Thus, should the vehicle be involved in an accident which might tend to separate the free edge wall '12 of the door from the body pillar 69 in a direction laterally of the direction in which the two are normally relatively movable, the plate 68 would permit limited movement of the bolt 14 laterally of the striker but not to such an ab tent as would permit the bolt to be disengaged in a lateral direction from the striker. Both the bolt and the retaining plate are made of steel having high strength characteristics adapted to withstand most any force except one that would literally tear the vehicle apart. As illustrated, in Fig. 4, the steel retaining plate is secured to the keeper frame by the same screws 70 adapted to mount the keeper on the vehicle body pillar 69.

1 claim: a

1. In a latch mechanism for a swinging door, a support having a main plate portion for disposition at the free edge wall of the door and having a flange extending from the inner edge of said main plate portion, latch device means pivotally mounted on said main plate portion, detent means pivotally mounted on said main plate portion for engagement with said latch device means, a swingable detent means release lever pivotally mounted on said plate portion and adapted to be operated from the outside of the door, said release lever having an extension extending toward said flange, a blocking lever pivotally mounted on said flange, said blocking lever having a hook portion adapted to engage said extension thereby to block swinging movement of said release lever, yieldable means normally urging said blocking lever into nonblocking position, and inner manually operable means operative in one direction to engage said extension to swing said release levercto disengage the detent means from said latch device and operative in the opposite direction to swing said blocking lever into blocking position, said inner manually operable means being effective to' hold said blocking lever in "blocking'position against the resistance of said yieldable means.

2. In -a latch mechanism for a swinging door, a support having a main plate portion for disposition at the free edge wall of the door and having a flange extending from the inner edge of said-main plateportion, latch device means pivotally mounted on said main plate portion, detent-means mounted on" said main plate portion for en- "gagement with said latch device means, a detent means release lever mounted-on saidmain' plate portion, said detent'means-and-release lever being mounted for inde- ,pendent pivotal movement about a common pivot axis, 'said release lever havingan extension-extending toward 'said flange,,a-blocking lever pivotally mounted on said 'flange, said blocking lever having ahook portion adapted to engage said extension thereby to block swingingmovement of said release lever, yieldable means normally urgingsaid blocking lever into non-blocking position, and inner manually operable means operative in one direction .to engage said extension to swing said release lever to disengage .the detent means from said latch device and opera- .tive in the opposite direction to swing said blocking lever i into blocking position, said inner manually operable means being effective to hold said blocking lever in blocking position against the resistance of said yieldablemeans. 3.' In a latch mechanism for a swinging door, a support .having a main plate portion for disposition at the free edge wallof the door and having a flange extending from ..the inner edge of said main plate portion, latch device means pivotally, mounted on said main plate portion for movement between door latchedand door unlatched positions, spring means normally urging said latch device means to door unlatched position, detent means mounted on said main plate portion engageable with said latch device means to maintain the same in door latched position, a detent means release lever mounted on said main plate portion, said detent ,means and release lever being mounted for independent pivotal movement about a common pivot axis, said release lever having an extension extending toward said flange, a blocking lever pivotally mounted on said flange, said blocking lever haying ahook portion adapted to engage said, extension thereby to block swinging movement of said release lever, said release lever being adapted to be blocked regardless of the posi- [tion of said latch device means, yieldable means normally urging said blockinglever into non-blocking position, and inner manually operable meansoperative in one "direction-to engage saidextension to swing said release lever to disengage the detentmeans from said latch device and operativein the opposite direction to swing and maintain said blocking lever in blocking position, said inner manually operable means being effective to hold said blocking lever in blocking position against the resistance ofsaid yieldable means.

4. In a latch mechanism for a swinging door, a support having a main plate portion for disposition at the free edge wall ofthe door and having a flange extending from the inner edge of said main plate portion, latch device means pivotally mounted on said main plate portion for movement between door latched and door unlatched positions, spring means normally urging said latch device means to door unlatched position, detent means mounted on said main plate portion engageable with said latch device means to maintain the same in door latched position, a detent means release lever mounted on said main plate portion, said detent means and release lever being mounted for coupled pivotal movement about a common -pivot axis, said release lever-having an extension extend- "ing toward said flange, a blocking lever pivotally mounted "on'said flange, said blockinglever-having a hook portion adaptedto. engage saidextension thereby to block swinging movement of said release lever, yieldable means normally urging said blocking lever into .non blocking position, inner manually operable means operative to swing said blocking lever in blocking position, said inner manually operable means being eflective ,to hold said blocking lever in blocking position against the, resistance of said yieldable means, and means effective to prevent blocking movement of said blocking lever whensaid latch device means is in door unlatched position.

V5. in a latch mechanism for a swinging door, a support having a main plate portion for disposition atthefree edge wall of the door and having a flange extending from the inner edge of said main plate portion, latchdevice means pivotally mounted on said main plate portion for movement between door latched and doorunlatched positions, spring means normally urging said latch device means to door unlatched position, detent means mounted on said main plate portion engageable with said latch demovement of said release lever, yieldable means normally urging said blocking lever into non-blocking position, inner manually operable means operative in one direction to engage said extension to swing said release lever to disengage the detent means from said latch device and operative in the opposite direction to swing said blocking lever in blocking position, said inner manually operable means being effective to hold said blocking lever in blocking position against the resistance of said yieldable means, and means effective to prevent blocking movement of said blocking lever when said latch device means is in door unlatched position.

6. In a latch mechanism for a swinging door, a support having a main plate portion for disposition at the free edge wall of the door and having a flange extending from the inner edge of said main plate portion, latch device means pivotally mounted on said main plate portion, detent means mounted on said main plate portion for engagement with said latch device means, a swingable detent means release lever pivotally mounted on said plate portion and adapted to be operated from the outside of the door, said release lever having an extension extending toward said flange, a blocking lever pivotally mounted on said flange, said blocking lever having a blocking portion adapted to engage said extension thereby to block swinging movement of said release lever, said blocking lever having an arm portion, spring means biasing 'said arm portion and normally urging said blocking lever into nonblocking position, and inner manually operable means including a bell crank lever having an arm operative upon said bell crank lever being swung in one direction to engage said extension to swing said release lever to disengage the detent means from said latch device, said arm being operative upon said bell crank being swung in the op posite direction to engage said arm portion and swing said blocking portion into blocking position, said arm being effective to hold said blocking lever in blocking position against the biasing force of said spring.

7. In a latch mechanism for a swinging door, a support having a main plate portion for disposition at the free edge wall of the door and having a flange extending from the inner edge of said main plate portion, latch device means pivotally mounted on said main plate portion, detent means mounted on said main plate portion for engagement with said latch device means, a swingable detent means release lever pivotally mounted on said plate portion and "adapted to be operated from the outside 'of the door, said release lever having an extension extending toward said flange, a blocking lever pivotally mounted on said flange, said blocking lever having a blocking portion adapted to engage said extension thereby to block swinging movement of said release lever, said blocking lever having an arm portion, spring means biasing said arm portion and normally urging said blocking lever into nonblocking position, inner manually operable means including a bell crank lever having an arm operative upon said bell crank lever being swung in one direction to engage said extension to swing said release lever to disengage the detent means from said latch device, said arm being operative upon said bell crank being swung in the opposite direction to engage said arm portion and swing said blocking portion into blocking position, said arm being eifective to hold said blocking lever in blocking position against the biasing force of said spring, and means efiective to prevent blocking movement of said blocking lever when said latch device means is in door unlatched position.

References Cited in the file of this patent UNITED STATES PATENTS Devereaux Mar. 22, 1927 Surprenant July 29, 1930 Potter Sept. 19, 1935 Lakin Feb. 11, 1941 Dall Jan. 15, 1952 Roethel Feb. 24, 1953 Dall July 7, 1953 Puzik Jan. 5, 1954 De Vito Apr. 6, 1954 Crockett May 25, 1954 Allen July 6, 1954 Roethel Aug. 30, 1955 Dingman et al Nov. 8, 1955 Dixon Aug. 14, 1956 Courtot Aug. 27, 1957 

